state: add environment persistency with UUID

worker/uniter/context.go

 package uniter
 
 import (
         "bufio"
         "fmt"
         "io"
         "launchpad.net/juju-core/log"
         "launchpad.net/juju-core/state"
-        "launchpad.net/juju-core/trivial"
         "launchpad.net/juju-core/worker/uniter/jujuc"
         "os"
         "os/exec"
         "path/filepath"
         "sort"
         "sync"
         "time"
 )
 
 // HookContext is the implementation of jujuc.Context.
 type HookContext struct {
         unit *state.Unit
 
         // config holds the service configuration.
         config map[string]interface{}
 
         // id identifies the context.
         id string
 
         // uuid is the universally unique identifier of the environment.
-        uuid trivial.UUID
+        uuid string
 
         // relationId identifies the relation for which a relation hook is
         // executing. If it is -1, the context is not running a relation hook;
         // otherwise, its value must be a valid key into the relations map.
         relationId int
 
         // remoteUnitName identifies the changing unit of the executing relation
         // hook. It will be empty if the context is not running a relation hook,
         // or if it is running a relation-broken hook.
         remoteUnitName string
 
         // relations contains the context for every relation the unit is a member
         // of, keyed on relation id.
         relations map[int]*ContextRelation
 }
 
-func NewHookContext(unit *state.Unit, id string, uuid trivial.UUID, relationId int,
+func NewHookContext(unit *state.Unit, id, uuid string, relationId int,
         remoteUnitName string, relations map[int]*ContextRelation) *HookContext {
         return &HookContext{
                 unit:           unit,
                 id:             id,
                 uuid:           uuid,
                 relationId:     relationId,
                 remoteUnitName: remoteUnitName,
                 relations:      relations,
         }
 }
@@ skipping 55 matching lines @@
 // into ctx.
 func (ctx *HookContext) hookVars(charmDir, toolsDir, socketPath string) []string {
         vars := []string{
                 "APT_LISTCHANGES_FRONTEND=none",
                 "DEBIAN_FRONTEND=noninteractive",
                 "PATH=" + toolsDir + ":" + os.Getenv("PATH"),
                 "CHARM_DIR=" + charmDir,
                 "JUJU_CONTEXT_ID=" + ctx.id,
                 "JUJU_AGENT_SOCKET=" + socketPath,
                 "JUJU_UNIT_NAME=" + ctx.unit.Name(),
-                "JUJU_ENV_UUID=" + ctx.uuid.String(),
+                "JUJU_ENV_UUID=" + ctx.uuid,
         }
         if r, found := ctx.HookRelation(); found {
                 vars = append(vars, "JUJU_RELATION="+r.Name())
                 vars = append(vars, "JUJU_RELATION_ID="+r.FakeId())
                 name, _ := ctx.RemoteUnitName()
                 vars = append(vars, "JUJU_REMOTE_UNIT="+name)
         }
         return vars
 }
 
@@ skipping 199 matching lines @@
                         }
                 }
         }
         if member {
                 ctx.members[unit] = settings
         } else {
                 ctx.cache[unit] = settings
         }
         return settings, nil
 }